[CentOS] What files to edit when changing the sdX of hard drives?

Mon Mar 4 00:03:33 UTC 2019
Jobst Schmalenbach <jobst at barrett.com.au>

On Fri, Mar 01, 2019 at 09:48:55AM -0600, Valeri Galtsev (galtsev at kicp.uchicago.edu) wrote:
> 
> 
> On 2/28/19 10:04 PM, Jobst Schmalenbach wrote:
> > On Thu, Feb 28, 2019 at 05:19:49PM +0100, Nicolas Kovacs (info at microlinux.fr) wrote:
> > > Le 28/02/2019 à 04:12, Jobst Schmalenbach a écrit :
> > > > I want to lock in the SDA/SDB/SDC for my drives
> > > 
> > > In short : use UUIDs or labels instead of hardcoding /dev/sdX.
> > 
> > I **KNOW** how to use UUID's ... this is NOT the reason why I am doing this!
> 
> Try to switch physical connections of second and third drives, then you most
> likely will have the correct "BIOS" order of physical drives. As, as far as

It seems I need to go that way as I learned that you cannot use UDEV to swtich the names of sdX as assigned by the kernel. You can only ADD (as in make an extra name) but not RENAME :-(.

It's weird though even in the BIOS they are assigned

 SDA (mirror 1)
 SDB (mirror 2)
 SDC (extra rsync/backup drive).

It's not nice, though. The problem arises because I will NEVER have a backup/rsync drive in a system when I do an install that includes resetting of partition tables of SOME of the drives - a backup drive is a holy grail.

So I created the mirror (i.e. partitioning and starting mdadm) withou the backup drive.

As soon as I put that one back in I cannot use and of the grub2 utils without those errors "missing drive" as suddenly the the mirrors are on SDA and SDC.

So there must be some bug somewhere as the grub2 utils do not look at the UUIDs but somehow at the hardware sdX.

Jobst


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